High-temperature vat dyeing baths using manganese compounds



Patented July 13, 1954 UNITED STATEfi... ATENT I OFFICE-J1HIGH-TEMPERATURE VAT DYEING BATHS USING MANGANESE COMPOUNDS FrederickFordemwalt, Middlescx, N. J., assignor 1 to American Cyanamid Company,New York, N. Y., a corporation of Maine No Drawing.- ApplicationNovember 1, 1952,

Serial No. 318,343

13 Claims. (Cl. 834) This invention relates to improved-reduction" bathscontaining alkali metal hydrosulfite and over-reduction buffers andthe'compositions for producing them.

In ordinary vat dyeing there is used a reduc-:

tion bath to transform the vat dye into its leuco form. This reductionbathis strongly alkaline.

and for the reducing material generally usesa metal hydrosulfite,usually sodium or zinc hydrosulfite. shown themselves sensitive toover-reduction in dyeing at elevated temperatures. This constituted aserious drawback in the cas of the sensitive dyes, as there is a greateconomic advantage in dyeing at high temperature. In Patents 1548;543

and 2,548,544, both dated April 10,1951; andlll Numerous vat dyes in thepast have Patent 2,576,846, dated November 27, 1951, there a have beendescribed processes for the high temperature dyeing of vat dyestufiswhich are sensi tive to over-reduction using certain over-reductionbuifers. In the two patents dated April- 10, 1951, the inorganicnitrites and halogenates are described and claimed, and inPatent-2,-5'76,846, dated November 27, 1951, organic nitrogen compoundsin which the nitrogen is attached 'b'yat least one co-valent bond tooxygen and by at least one co-valent bond to an element other -thanoxygen or nitrogen are described and claimed:

These compounds stabilized the dyestuffs and prevented over-reduction.The same compounds were also found to improve the dyeing with oer-1 tainpyranthrone vat dyestuffs'whichare'not" sensitive to over-reduction.Processes using"? nitrites and halogenates in the dyeing-of thesedescribed solve the problem presented by over--- reduction of sensitivevat dyestuffs in high tern-H perature dyeing and improve the :dyeingofthe.

pyranthrone dyestuffs referred to above.--.H0w-= ever, this greatlyimproved resultwas obtained. at

the expense of increased hydrosulfite consumption and while theconsumption'of hydrosulfite is not so great as to renderthe improved dyeprocesses uneconomical, the cost of the increasedhydrmsulfiteconsumption is nevertheless sufficient" so that reduction of theexcessive consumption economically desirable.

The mechanism w h ults n increased hjyable when thebathcontainsonly-thestabilizing drosulfite consumption "is notfullydetermined;

but appears to be due at least-in part-to chemical reaction with thestabilizeror over-reduction."

buffer.

According to the present invention, I have' found that if a substantialamount of manganese compound is introduced into the bath,.theexcessconsumption of hydrosulfite at high temperatures is very greatlyreduced and as aresult on stand-- ing the hydrosulfite concentration ismuch-higher than if the bath contained no manganese-ions; It is notknown just howthe presence of the manganese compoundreduces-excessive-hydro-' sulfite consumption and thereforethe-invention is not restricted to a particular theory'of how-itbehaves. It is possible that a manganese salt or complex of thehydrosulfite may be formed which is less'reactive with the stabilizersor overreduction buffers than the alkali salts.- -*However; though thismay be a factor, it seems probable: that it is not the only factorbecause manganese ions are effective in amounts very materially less"than the stoichiometrical equivalents-necessary for forming manganesehydrosulfite:

The preparation of baths has been described above in terms of addingingredients to the bath. In manycases this is preferable, :but it isalso possible to produce-compositions.containingmhe' vat dyestuff andthe manganese. suchrcomposis;

tions contain suflici'ent manganese so that when a vat dye bath isprepared in the normal manner the manganese counteractsthe'hydrosulfiteconsumption. Thusrit is possi-blezto marketia com- The'over-reduction buffers are substantial equivalents and .thepresentinvention is therefore applicable regardless of whether ther'e-is asingle bufier'present or a mixture of two or more Of them.

While manganese compounds of the'presentinvention mayalsobe usedwithother compounds having the same effect, namely; magnesium compoundsand trialkanolamine's, theseother compounds are not claimed perse inthis case but constitute the subject matter of the copendingapplications of Jerry M. Mecco,'Serial No.-258,281, filed November 26,l951,'and Serial No.-253;282;

filed November 26, 1951, both now abandoned.

The operation of the present invention is not limited to vatdyeing'baths in which the vat dye Similar is actually incorporated intothe bath.

savings in hydrosulfite consumption-are obta'in agent or over-reductionbuffer and the hydrosulfite as in the case of certain pigment dyeingprocesses.

The invention will be described in greater detail in conjunction withthe following specific examples, the parts being by Weight unlessotherwise specified.

Example I A dye bath was prepared to contain 400 parts of a solutioncomposed of the following materials: 10.0% 30 B. caustic soda, 0.75%sodium nitrite, 8.7% of a 1% dispersion of a commercial paste of the vatdye having Color Index No. 1113, 80.55% water.

To this were added 4 parts of a solution of manganous chloride(MnCl2-4H2O). The bath was heated to the boil and then 12.5 parts ofsodium hydrosulfite were added.

The temperature was maintained at the boil for 23 minutes, at which timethe bath was found still to contain 5 parts of hydrosulfite asdetermined by titration with a standard indigo solution. At the end of30 minutes, a swatch of 80 x 80 bleached unmercerized cotton print clothwas introduced into the bath and dyed for minutes at the boil. Theresult was an excellent strong blue dyeing.

In a similar bath which contained no man ganese salt, the hydrosulfiteconcentration during the dyeing period decreased to less than 1.2 partsin 10 minutes time, and no hydrosulfite remained after 18 minutes. Aswatch of cotton cloth, similar to the above, which was introduced intothe bath at the end of 30 minutes remained essentially undyed.

Example 2 The procedure of Example 1 was repeated except only 3 parts ofthe manganese chloride solution were used. The bath contained 3,6 partsof hydrosulfite after 23.5 minutes and the cotton cloth introduced atthe end of 30 minutes became strongly dyed as compared to a controldyeing which was essentially undyed.

Ezvample 3 The procedure of Example 1 was repeated except only 2 partsof the manganese chloride solution were used.

After eleven minutes, the bath still contained 8.5 parts of hydrosulfitewhereas a similar bath without the manganese salt had less than 1.2parts of hydrosulfite after 10 minutes.

Example 4 A dye bath was prepared to contain 4 oz./gal. sodiumhydroxide, 4 oz./gal. sodium hydrosulfite, 1 oz./ga1. sodium nitrite,0.1 oz./gal. of a commercial paste of the blue vat dye having ColorIndex No. 1113 and 0.25 oz./gal. of hydrated manganese chloride. Therate of hydrosulfite consumption at the boil was approximately 0.16oz./gal./min. In a corresponding bath with no manganese salt present,the hydrosulfite consumption was more than twice as rapid.

Example 5 A dye bath (having no dye present) containing 4 oz./gal.sodium hydroxide, 1 oz./gal. sodium nitrite, and 4 oz./gal. sodiumhydrosulfite was held at a temperature of approximately 200 Thehydrosulfite consumption amounted to approximately 03 oZ./gal./min. In acorresponding bath which contained, in addition 0.12

oz./gal. of hydrated manganous chloride, the r e of hydrosulfiteconsumption was only about 0.1 oz./gal./min.

Emample 6 A dye bath which contained 4 oz./gal. sodium hydroxide, 0.1oz./gal. sodium nitrite, 4 oz./gal. sodium hydrosulfite, and 0.1oz./gal. of a commercial paste of the orange vat dye having Color IndexNo. 1098 was heated to approximately 200 F. for 30 minutes. At the endof this time, the hydrosulfite content was approximately 3.3 oz./gal.and 1 oz./gal. sodium nitrite was then added. The hydrosulfiteconsumption then became about 0.7 oz./gal./min.

Ercample 7 The procedure described in Example 6 was repeated except thebath contained, in addition, 0.2 oz./ga1. hydrated manganese chloride.The hydrosulfite consumption in this case was only about one-fourth asrapid as under the conditional of Example 6.

Example 8 The procedure described in Example 7 was re peated except thatthe dye used was the pink vat dye having the formula: 6,6dichloro-4,4-dimethyl 2,2bis(thio)naphthene indigo. The hydrosulfite consumption wasapproximately the same as that observed under the conditions describedin Example '7.

Example 9 A dye bath containing 4 oz./gal. of sodium hydroxide, 1oz./gal. of sodium nitrite, 0.08 oz./gal. of a commercial paste of thegreen vat dye having Color Index No. 1101, and 0.07 oz./gal. manganesesulfate technical grade was heated to approxi mately 200 F. and 4 oz./gal. sodium hydrosulfite were then added. The rate of hydrosulfiteconsumption in this bath was only about one-half as great as in acorresponding bath which contained no manganese salt.

A piece of x 80 bleached unmercerized cotton cloth introduced into thebath at the end of 30 minutes and dyed for 10 minutes became heavilydyed. A piece of similar cloth introduced into the corresponding bathwhich contained no manganese salt remained undyed.

Example 10 The procedure of Example 9 was repeated using manganeseresinate instead of manganese sulfate. The results were generallysimilar to those described in Example 9.

Example 11 The procedure of Example 9 was repeated using 0.03 oz./gal.hydrated manganese chloride instead of the manganese sulfate.

The results were generally similar to those described in Example 9.

Example 12 The procedure of Example 9 was repeated using 0.01 oz./gal.hydrated manganese chloride instead of the manganese sulfate. Again, agood dyeing was obtained with the bath which contained the manganesesalt.

Example 13 A dye bath which contained 4 oz./ga1. NaOH, 0.1 oz./gal. of acommercial paste of the blue vat dye having C. I. No. 1113, 2 oz./gal.of hydroxylamine hydrochloride and 0.01 oz./gal. of hydrated manganesechloride was heated to approximately 200 F. and 4 oz./gal. of sodiumhydrosulfite added. At the same timea secondw bath was prepared inexactly thesame way :ex-

cept no maganese salt was added. The rate of hydrosulfite consumption,as measured'by titration with standard indigo, .was over twice as fastin the bath which contained no manganese as it was in the bath to whichthe manganese salt had been added.

A swatch of 80 x 80 cotton introducedinto the first bath at the end ofeleven minutes became heavily dyed while a swatch introduced at the sametime into the bath to which no manganese had been added remainedessentially undyed.

Example 14 A bath which contained 4 oz./gal. of NaOI-I, 0.04 oz./gal. ofa commercial paste of the blue vat dye having C. I. No. 1113 and 2oz./gal. of NaClO3 was heated to approximately 200 F. and 4 oz./ gal. ofsodium hydrosulfite added.- The rate of hydrosulfite consumption in thisbath was approximately 0.19 'oz./ga1./min. In a corresponding bath towhich 0.01 oz./gal. of hydrated manganese chloride had been added thhydrosulfite consumption was less than one-half as great.

Example In a bath prepared as described in Example 14 but with no dyepresent, the rate of hydrosulfite consumption was approximately-0.22oz./gal./min.

without the manganese and only about one-half that fast in the bathwhich contained the manganese salt.

Example 16 A bath which contained 4 oz./gal, of NaOI-I and 2 oz./ gal.of hydroxylammonium sulfate was heated to about 200 F, and 4 oz./gal. ofsodium hydrosulfite added. The rate of hydrosulfite consumption,measured by titration with a standard indigo solution, was approximately0.33 oz./gal./min In a corresponding bath to which had been added 0.01oz./gal. of hydrated manganese chloride the hydrosulfite consumption wasonly about 0.22 oz./ gal. /rnin.

Example 17 Two dye baths were set up, each containing a oz./gal. ofNaOI-I, l oz./gal. of NaNOz, 0.1

oz./ gal. of a commercial paste of the blue vat dye having C. I. No.1113 and 4 oz./gal. of zinc hydrosulfite. One of the baths contained, inaddition, 0.03 oz./ gal. of hydrated manganese chloride.

Titrations with standard indigo showed that, r

in the bath which did not contain the manganese compound, thehydrosulfite consumption was about more rap-id than it was in the otherbath in which the manganese ions were present.

Example 18 ExampleIQ parts of the real dye having Color Index No. 1106in the'form'of a press cake were dispersed with 5 parts ofdisodiumdisulfodinaphthylmethane. To this were added 50 parts ofmanganous chloride after which the mixture was passed through a high*speedmixer. This gave a vat dye composition containing the 'manganoussalt.

A dye bath was prepared to contain 5 parts of the above paste, 4Qa/galNaOH, 1 oz./gal. sodium nitrite and 4 oz./gal.'sodiumhydrosulfite. When cotton was dyed in this dye bath at a temperature of200 F., the rate at which the hydrosulfite was consumed was less thanthe rate of consumption in a similar dye bath-in which no manganous saltwas present.

Example 20 The following dye mixtures were prepared using 100 parts ofthe dye having ColorIndex No. 1105 in the form of a dispersed press cakeas in the preceding example:

100 parts dye-25 parts manganous chloride 100 parts dye12parts-manganous chloride 100 parts dye6 parts manganous sulfate 100parts dye-13 parts manganous sulfate When these were dyed on cotton bythe pro cedure of Example 19, good blue shades were obtained.

If desired, the dyes having Color Index Nos. 1112, 1113, 1098, 1101, maybe used in place of the dye having Color Index No. 1106. 1

Example 21 100 parts of the dye of Example 19 in the form of a presscake were dispersed as in Example 19 and then colloidized by the generalprocedure of ,U. S. Patent No. 2,090,511,'except that 50 parts ofmanganese chloride were used to replace 50 parts of cerelose. Theproduct was a colloidized vat dye containing a manganese salt.

This powder was used to make a 5% dyeing by the procedureof Example. 19and no difference was noted.

Example 22 The procedure of the precedingiexample'was' repeated exceptthe manganese salt-was added to the defiocculated press cake beforecolloidizing. It was then blended with the requisite quantity of sugar.

Dyes having Color Index Nos. 1106, 1112, 1098, 1101 and 1117 werecolloidized by the methods outlined above and in Example 21 and thecolloidized powders were substituted for the paste in making dyeingsaccording to the process described in Example 19. The results weresatisfactory.

Example 23 Two dye baths were set up, each containing 4 oz./gal. ofNaNOz, 0.1 oz./gal. of a commercial paste of the blue vat dye havingColor Index 1113, and 4 oz./gal. of zinc hydrosulfite. One of the oathscontained, in addition, 0.03 oz./gal. of man-- ganese chloride.

Titrations with standard indigo showed that, in the bath which did notcontain the manganese compound, the hydrosulfite consumption was about50% more rapid than it was in the other bath in which the manganese ionswere present.

Example 24 A dye bath was prepared to contain 50 parts of a 1% slurry ofthe vat dye having Color Index No. 1113, 15.8 parts of 30 B. NaOI-lf,1.5 parts of NaNOz, 130 parts of H20 and 2.6 parts of a 3% solution ofKMnO4. This was heated to 196 F. and there were then added 6 parts ofsodium hydrosulfite. The bath was stirred frequently while thetemperature was held at 197-198 F. The amount of hydrosulfite wasdetermined at intervals by titration with soluble indigo. After minutesa swatch of 80 x 80 cotton was introduced and dyed for 6 minutes. Astrong bluecolor was obtained and after 18 minutes the bath stillcontained approximately two parts of hydrosulfite.

Another dyebath was prepared as above with the omission of the 2.6 partsof the potassium permanganate solution. After five minutes thehydrosulfite was practically gone. After seven minutes the dye startedto precipitate in the bath, and the swatch of cotton introduced at theend of ten minutes and dyed for six minutes remained essentiallyuncolored.

Example A dye bath was prepared to contain 0.5 part of a commercialpaste of the vat dye having Color Index No. 1113 and containing 0.1 partreal dye, 6.0 parts of NaOH, 1.5 parts of NaNOz, 0.12 parts ofMgSO4'7I-I2O, 0.078 part of mm and 200.0 parts of water.

The bath was heated to approximately 200 F. and held at thattemperature. 6.0 parts of Na2S2O4 were added and the bath stirredfrequently.

Titration with a standard solution of soluble indigo showed that at theend of 12 minutes there were still approximately 3.5 parts ofhydrosulfite remaining in the bath.

A similar bath was prepared omitting the magnesium sulfate and thepotassium permanganate and after 10 minutes the hydrosulfite wasentirely consumed.

I claim:

1. A reducing bath suitable for high temperature vat dyeing comprisingan aqueous solution of caustic alkali and metal hydrosulfite, astabilizer against over-reduction of vat dyes selected from the groupconsisting of inorganic nitrites, inorganic halogenates and nitrogencompounds in which a nitrogen atom is attached by at least one co-valentbond to oxygen and by at least one co-valent bond to an element otherthan oxygen or nitrogen and at least 0.0005 mol of a manganese compoundper mol of metal hydrosulfite.

2. A bath according to claim 1 containing a vat dyestufi capable ofover-reduction at elevated temperatures.

3. A bath according to claim 1 containing a pyranthrone vat dyestuif.

4. A bath according to claim 1 in which the stabilizer is alkali metalnitrite.

5. A bath according to claim 2 in which the stabilizer is alkali metalnitrite.

6. A bath according to claim 5 in which the vat dyestuff is a vatdyestufi of the indanthrone series.

7. A bath according to claim 3 in which the stabilizer is alkali metalnitrite.

8. A bath according to claim 1 in which the stabilizer is a nitrogencompound linked by at least one co-valent bond to oxygen and by at leastone co-valent bond to an atom other than oxygen or nitrogen.

9. A bath according to claim 8 containing a vat dyestufl capable ofover-reduction at elevated temperatures.

10. A bath according to claim 9 in which the nitrogen compound is ahydroxylamine compound.

ll. A bath according to claim 10 in which the vat dyestufi is a dyestufiof the indanthrone series.

12. A bath according to claim 1 in which there is present in addition tothe manganese compound at least one compound selected from the groupconsisting of soluble magnesium compounds and trialkanolamines.

13. A bath according to claim 12 containing a vat dyestuff capable ofover-reduction at elevated temperatures.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,584,202 Theobald May 11, 1926 2,067,927 Kern Jan. 19, 19372,067,928 Kern Jan. 19, 1937

1. A REDUCING BATH SUITABLE FOR HIGH TEMPERATURE VAT DYEING COMPRISINGAN AQUEOUS SOLUTION OF CAUSTIC ALKALI AND METAL HYDROSULFITE, ASTABILIZER AGAINST OVER-REDUCTION OF VAT DYES SELECTED FROM THE GROUPCONSISTING OF INORGANIC NITRITES, INORGANIC HALOGENATES AND NITROGENCOMPOUNDS IN WHICH A NITROGEN ATOM IS ATTACHED BY AT LEAST ONE CO-VALENTBOND TO OXYGEN AND BY AT LEAST ONE CO-VALENT BOND TO AN ELEMENT OTHERTHAN OXYGEN OR NITROGEN AND AT LEAST 0.0005 MOL OF A MANGANESE COMPOUNDPER MOL OF METAL HYDROSULFITE.